1. Field of the Invention
The invention is directed to a process for regulating individual factors or all factors influencing combustion on a furnace grate.
2. Description of the Related Art
It is known from DE 38 25 931 C2 to regulate the firing capacity or furnace performance of incinerating installations by observing the burn-up behavior of the fuel on the firing grate via an infrared camera and regulating the air supply zonewise corresponding to the temperature distribution determined by the infrared camera. Although this regulating method resulted in considerable improvements over previous processes, it is still not satisfactory insofar as it enables only the temperature to be determined, but does not permit any conclusions to be reached concerning the amount of energy liberated by combustion in the individual zones. Accordingly, the furnace output or performance cannot be adapted with sufficient precision and speed to the steam output requirement.
In addition to this known method of regulating the combustion process based on determination of temperature in order to achieve a determined furnace performance, it is known to regulate the furnace performance as a function of the oxygen content detected in the flue gas or as a function of the generated mass flow of steam.
In all three regulating methods, there is a tendency to overcharge the grate when there is a drop in the thermal value of the fuel reaching the grate. For example, when there is an increase in the oxygen content of the exhaust gas, the regulating mechanism cannot determine whether this is a result of a decreasing thermal value or is caused by a decrease in the amount of fuel charged, so that the feed quantity is increased. When regulating on the basis of temperature and mass flow of steam, circumstances are such that when there is a decrease in the flue gas temperature and a reduction in the mass flow of steam the regulating device will likewise proceed on the assumption that the fuel mass located on the grate is insufficient and will increase the feed quantity. Since continuous detection of thermal values in refuse incineration plants is not possible, the grate will sometimes be overcharged due to the circumstances mentioned above.